Well, I bought this notebook a year ago, and it came with Windows 7, so I had no serious qualms about trying Windows 8 on it. It's OK so far, no serious problems and only a couple of niggles. I had all my data backed up anyway, but the upgrade went smoothly and I didn't need to restore or reinstall anything.
In the long term for this laptop, however, Windows will be coming off and Linux going on. Windows 7/8 is only acceptable because it's a powerful machine (Intel Core i5, 4GB RAM), and I have a few Windows applications that I need to work flawlessly for the next couple of months.